Are you asking for the motion controls of the standard Wii Remote, or MotionPlus controls? I think the former already is supported if you're not using the on-screen controls, and there are currently no plans to add emulated MotionPlus to Dolphin on any platform because of how complex it is.

I know former controls are added but 98 percent of Wii games require motion controls and it can be fix just try to fix axis problem on Wii d pad or add only GameCube d pad for Wii games as it can be used as option controls u have not observed it but see this pic below .Plz at least add one GameCube d pad on on Wii+nunchuk controls add GameCube d pad and all the problem is sort out but I have observed in GameCube d pad that only up and down works for Wii motion for left and right try to find correct axis